1. Field of the Invention
The present invention relates to a video signal processing apparatus for use in a video tape recorder (VTR).
2. Description of the Prior Art
To raise the S/N ratio of the video signal processed in VTR's, a recursive filter has been used for video signal processing. The recursive filter involves a delay circuit for delaying the video signal by 1H or 2H (H: horizontal synchronization period). The filter feeds output of the delay circuit back to the input thereof to average the signal noise, thus raising the video signal S/N ratio.
With the conventional circuit construction, however, when the video signal has a low vertical correlation, i.e. when the signal input to the recursive filter shows a sudden change, the filter cannot follow the output change promptly. If such a circuit is used in processing color signals, a delay in color change causes a downward color offset (color offset in a downward direction on the TV screen due to the color signal delay with respect to the luminance signal). If the luminance signal is processed with this circuit, the vertical resolution will deteriorate.